Birchbox does automatically what women wish they had the time to do: find cool, new beauty and skin-care samples. Each month, the five-year-old company sends out boxes to 1 million women worldwide filled with four to five sample-sized beauty, grooming and skin-care products from companies big and small. The service costs $10 a month, and the items in each box are selected based on a user's profile and beauty preferences.

Birchbox launched a similar subscription service for men in 2012. When a customer falls in love with one of the samples, he or she can order a full-size version right from the company's e-commerce site.

Revenues last year were estimated to be about $125 million. Co-founders Katia Beauchamp and Hayley Barna are former classmates at Harvard Business School and run the New York City-based company as co-CEOs. So far, investors like their subscription formula. Viking Global Investors, First Round Capital and Accel Partners have invested almost $72 million in the company to date.

"You can purchase anything that you love, so it’s the whole 360 degrees of discovery, and that’s really what we thought was missing. It’s hard to discover beauty. There are thousands of products."-Katia Beauchamp, co-founder